Thanks for the reply, that's good news. I don't know if I could even find the spot I picked this up at, the area is pretty dense and right now you can't step on anything but fallen wood and leaves so it's pretty jumbled.

I hadn't gotten any replies so I went ahead and prepped the wood from the 3rd set. Soaked for a few days, put it in the oven for 2 hours at 250. Soaked again for a day then into the tank.

Seems to be working well. I anchored it to keep it down and after some trimming it looks like this:

still needs to be adjusted and centered a bit but I couldn't get it anchored anywhere else. So it's got to wait until it fully sinks.

Thanks again for the help!

Yeh the 3rd set looks like oak to me so I'm sure you're fine. Nice jungle of plants you got there.